构造煤裂隙各向异性井下检测及反射P波AVAZ正演模拟

项目名称： 构造煤裂隙各向异性井下检测及反射P波AVAZ正演模拟

项目编号： No.40804026

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 陈同俊

作者单位： 中国矿业大学

项目金额： 18万元

中文摘要： 构造煤相对于原生煤来说其次生裂隙发育，为瓦斯突出提供了通道。因此，煤矿瓦斯灾害直接与构造煤有关。在本次项目中，首先通过矿井地震波原位测试，获得了矿井的原位地震测试记录，通过对其的各向异性分析，获得了矿井原位各向异性参数。第二，以获得的各向异性参数为基础，建立了VTI构造煤、裂隙型HTI构造煤和ORT构造煤的正演模型，以Hudson等效各向异性介质理论为基础，计算了其速度各向异性和各向异性参数。第三，以孔隙等效各向异性介质理论为基础，研究了渗透率对上述裂隙型HTI构造煤和ORT构造煤各向异性参数的影响。第四，对上述所建立的构造煤模型利用Schoenberg的方法，计算了不同顶底板条件下构造煤的方位AVO和AVAz曲线，并分析了构造煤裂隙的可探测性。同时，正演模拟了其AVO地震记录。第五，利用CT成像方法，对所测试矿井工作面内的P波和S波速度分布进行了层析CT反演，获得了P波和S波在矿井工作面内的分布。最后，对所采集的矿井岩样和煤样进行了超声测试，获得了矿压与P波和S波速度间的定量关系。总之，本次项目为利用地面P波资料研究煤层裂隙提供了可靠的原位测试数据，并在理论上分析了其可行性。

中文关键词： 煤层裂隙；原位测试；等效介质；各向异性；方位AVO

英文摘要： Relative to primary coal, tectonic coal has sufficient fractures and those fractures are the effusion channel of coal bed methane(CBM). So, we can concluded that the disasters of CBM associate with tectonic coal directly. In this project, two in site seismic tests were adopted at coal mine underground to achieve original seismic records. After the analyzing of those records, the in site anisotropic parameters at coal mine underground were obtained. Secondly, some forward models of VTI coal, fractrued HTI coal and ORT coal were built based on the achieved anisotropic parameters, and the velocity anisotropy and anisotropic parameters of foregoing models were calculated by Hudson's effective medium theory. Thirdly, the permeability effect on anisotropic parameters of fractured HTI coal and ORT coal was studied by equivalent pore anisotropic medium theory. Forthly, the azimuthal AVO and AVAz curves of tectonic coal with different roof and floor were computed by using of Schoenberg's calculation method, meanwhile the detectability of tectonic coal fractures was analyzed too. Fifthly, the velocity distributions of P-wave and S-wave on underground mine face were inverted by using of CT imaging method. Finally, some rock and coal samples collected from coal mine underground were used to make ultrasonic test. After this testing, the quantitative relationship between rock pressure and P-wave and S-wave velocity was achieved too. In a word, this project provided reliable in site seismic test results to support coalbed fracture dectecting by using of surface P-wave seismic, and analyzed its theoretical feasibility.

英文关键词： coal fractures; in site test; effective medium; anisotropy; azimuthal AVO